Earthquake is one of the most destructive natural disasters in China.For a long time

investigation of earthquake damage has been based on field surveys

but disadvantages of this means

such as huge workload

low efficiency

too much expense and un-visualized information

make it not practical.However

remote sensing technique can provide a rapid and effective approach for quick investigation and assessment of earthquake damage

owning to its characteristics of objectivity

real-time and macro-scope view.The history of investigation and assessment of earthquake damage based on remote sensing in China: Since mid of 1960s

institutes and departments of Chinese Academy of Sciences have done a lot of work on quake damage investigation and assessment and accumulated rich experience.Aerial photography was carred out for Xingtai quake in 1966

Haicheng earthquake in 1975

Tangshan quake in 1976 and Lancang-Gengma earthquake in 1988 and the mornitoring and mapping for earthquake damage were accomplished in different scales.All of these achievements provided important scientific basis for decision-making of the earthquake relief and reconstruction.With the development of remote sensing technique for decades

this technology supplies technical support and priori knowledge for the investigation and assessment of Wenchuan quake damage.There occurred open ended Richter 8.0 scale earthquake in the county of Wenchuan

Sichuan province on May 12th

2008

which has caused huge destructive losses.In this

the remote sensing technique is used to investigate and paper assess the situation of the earthquake damage.There are five classes of features which can be interpreted according to the remote sensing imageries:（1） the damage degree of buildings

like civilian homes

factories

schools

hospitals and so on

which is related to the safety of human life and property directly;（2） the damage degree of structures

such as television towers

chimneys

oil tanks

power houses and etc.

which can indicate the intensity of the earthquake;（3） the damage degree of the lifeline

for example

the highway

railway

bridge

power and communication supply

which are very important for disaster relief and human’s life after the earthquake;（4） the field disasters of earthquake

such as landslides

debris flows

ground fissures;（5）the secondary disasters caused by field disasters

like quake lakes

emission of harmful gases.All of these five classes of features are the main data for determinating the intensity of earthquake and the degree of damage.The features can be obtained according to different spectral and spatial resolution of remote sensing imageries

through image processing and interpretation methods.Besides

other kinds of data can also be imported for assistant interpretation.The work flow includes remote sensing image processing

human-machine interactive classification

location

qualitative and quantitative information extraction

GIS-support assessment of earthquake damage

mapping of damaged objects.In this study

the radar images are used.Due to the bad weather after the earthquake

and the optical remote sensing cannot get useful information.As a result

the all-weather radar sensor can provide lots of information and the 1m spatial resolution radar images have played an important role in the investigation.Certainly

the optical remote sensing imageries also played an important role.Using kinds of remote sensing images

the abundace of landslides

collapse debris flows

the rate of building damages

the situation of quake lakes and road damage are interpreted.In conclusion

remote sensing technique can play an important role in the investigation and assessment of earthquake damage.Of course

remote sensing application in WenChuan quake shows some shortcomings

and it may be improved and developed in five aspects as follows.（1） It is important to select imageries and high spatial resolution imageries are significant.（2） The basic database is needed to be built.（3） Quick interpretation techniques should be developed.（4） It is more practical to use human-computer interactive interpretation extract earthquake information.（5） In investigation of earthquake damages

data process techniques of 3D rebuild will quickly be developed and remote sensing

GIS and GPS techniques will be combined and applied to the investigations in wider and higher level.